From 76154e282cbf409aaa938ddefcaf904b5ab5d226 Mon Sep 17 00:00:00 2001
From: kettenis <kettenis@openbsd.org>
Date: Sat, 1 May 2021 12:29:05 +0000
Subject: [PATCH] Implement early console functionality based on available SBI
 calls.

While these calls are part of the legacy extensions and deprecated, they
are really useful for debugging purposes.

ok jsg@
---
 sys/arch/riscv64/conf/files.riscv64 |  2 --
 sys/arch/riscv64/riscv64/machdep.c  | 10 ------
 sys/arch/riscv64/riscv64/sbi.c      | 56 ++++++++++++++++++++++++++---
 3 files changed, 51 insertions(+), 17 deletions(-)

diff --git a/sys/arch/riscv64/conf/files.riscv64 b/sys/arch/riscv64/conf/files.riscv64
index 2e08f6b1d0b..6111eec5a5d 100644
--- a/sys/arch/riscv64/conf/files.riscv64
+++ b/sys/arch/riscv64/conf/files.riscv64
@@ -8,8 +8,6 @@ major	{ sd = 0 }
 #major	{ wd = 4 }
 major	{ rd = 8 }
 
-file	dev/cninit.c
-
 file	arch/riscv64/riscv64/autoconf.c
 file	arch/riscv64/riscv64/ast.c
 file	arch/riscv64/riscv64/bus_space.c
diff --git a/sys/arch/riscv64/riscv64/machdep.c b/sys/arch/riscv64/riscv64/machdep.c
index 834631f275e..90da72abc14 100644
--- a/sys/arch/riscv64/riscv64/machdep.c
+++ b/sys/arch/riscv64/riscv64/machdep.c
@@ -75,8 +75,6 @@ struct vm_map *phys_map = NULL;
 
 int physmem;
 
-//struct consdev *cn_tab;
-
 caddr_t msgbufaddr;
 paddr_t msgbufphys;
 
@@ -180,12 +178,6 @@ consinit(void)
 	com_fdt_init_cons();
 }
 
-//XXX TODO: need to populate console for qemu
-//maybe no longer needed, as already have cn_tab ??
-struct consdev constab[] = {
-	{ NULL }
-};
-
 void
 cpu_idle_enter(void)
 {
@@ -919,5 +911,3 @@ pmap_bootstrap_bs_map(bus_space_tag_t t, bus_addr_t bpa, bus_size_t size,
 
 	return 0;
 }
-
-
diff --git a/sys/arch/riscv64/riscv64/sbi.c b/sys/arch/riscv64/riscv64/sbi.c
index a988a652253..02deb807cc7 100644
--- a/sys/arch/riscv64/riscv64/sbi.c
+++ b/sys/arch/riscv64/riscv64/sbi.c
@@ -25,17 +25,14 @@
  * SUCH DAMAGE.
  */
 
-#include <sys/cdefs.h>
-
 #include <sys/param.h>
 #include <sys/systm.h>
 #include <sys/types.h>
 
-#if 0
-#include <machine/md_var.h>
-#endif
 #include <machine/sbi.h>
 
+#include <dev/cons.h>
+
 /* SBI Implementation-Specific Definitions */
 #define	OPENSBI_VERSION_MAJOR_OFFSET	16
 #define	OPENSBI_VERSION_MINOR_MASK	0xFFFF
@@ -167,3 +164,52 @@ sbi_init(void)
 	KASSERTMSG(sbi_probe_extension(SBI_SHUTDOWN) != 0,
 	    "SBI doesn't implement sbi_shutdown()");
 }
+
+/*
+ * Early console implementation based on the Console Putchar and
+ * Console Getchar legacy extensions.  These extensions are deprecated
+ * but extremely useful for bringing up new boards.
+ */
+
+void
+sbi_cnprobe(struct consdev *cd)
+{
+}
+
+void
+sbi_cninit(struct consdev *cd)
+{
+}
+
+int
+sbi_cngetc(dev_t dev)
+{
+	int c;
+
+	for (;;) {
+		c = sbi_console_getchar();
+		if (c != -1)
+			return c;
+	}
+}
+
+void
+sbi_cnputc(dev_t dev, int c)
+{
+	sbi_console_putchar(c);
+}
+
+void
+sbi_cnpollc(dev_t dev, int on)
+{
+}
+
+struct consdev sbi_consdev = {
+	.cn_probe = sbi_cnprobe,
+	.cn_init = sbi_cninit,
+	.cn_getc = sbi_cngetc,
+	.cn_putc = sbi_cnputc,
+	.cn_pollc = sbi_cnpollc,
+};
+
+struct consdev *cn_tab = &sbi_consdev;
-- 
2.20.1